JPH0529178A - Manufacture of film capacitor - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a film capacitor having excellent mechanical performance and electric characteristics. CONSTITUTION:A metallized film 1 and a metallized film 2 are wound or laminated to obtain an element body, electrodes are formed at both ends of the body, and leads are connected to the electrodes thereby to constitute a capacitor C. At the time of a step of winding or laminating the films 1, 2, the films 1, 2 are fed through steps of heating and pressurizing them by a roller 3 or 4 at each layer, thereby obtaining the body having no air gap.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a film capacitor which is resistant to heat, has a high corona voltage, and is free from vibration caused by voltage application.

[0002]

2. Description of the Related Art Conventionally, as is well known, a metallized film capacitor has a structure in which lead wires are connected to both ends of a metallized film obtained by winding or laminating metallized film.

6 and 7 are views for explaining a method of manufacturing a conventional metallized film capacitor.

In this figure, metallized films 11, 1
Reference numeral 2 is formed by vapor-depositing the metal A on the film F and integrating them, and the metallized films 11 and 12 are provided with a certain margin. Such metallized films 11,1
2 are stacked and wound as shown in FIG. 6 to form a wound capacitor. Further, the metallized films 11 and 12 are stacked and wound around the drum 13 as shown in FIG. 7 (a) to form a laminated capacitor. The element body thus obtained is heated and pressed, and thereafter, the metal is sprayed onto each metal A on both end faces of the element body to form electrodes.
As for the laminated type, as shown in FIG. 7 (b), the laminated body is removed from the drum 13, cut into strips, and lead wires are welded to these electrodes to form a wound or laminated metallized film. You're getting a capacitor.

[0005]

However, in this type of capacitor, since the element body is wound and then pressure is applied while heating, an air gap remains in the metallized film layer, and the remaining portion thereof remains. There is a problem that it is easy to absorb moisture, and when heated, the exterior resin is cracked due to expansion of air in the air gap, corona discharge is likely to occur, and it becomes a source of vibration noise when an AC voltage is applied. ..

In order to solve such a problem, a manufacturing method of impregnating an impregnating agent to remove air is adopted.
The above problems could not be completely eliminated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a film capacitor manufacturing method for manufacturing a film capacitor excellent in mechanical performance and electrical characteristics.

[0008]

In order to solve the above-mentioned problems, a method for producing a film capacitor according to the present invention is a method for producing a capacitor by winding or laminating a metallized film. The present invention is characterized in that a capacitor is formed through a process of heating and pressurizing the metallized film layer by layer in the process of taking or laminating.

[0009]

According to the present invention, in the step of winding or laminating the metallized film, the metallized film is heated while being pressed by one layer so that the metallized film is randomly or entirely spread from the winding start portion to the winding end portion. It is welded. Therefore, no air gap is generated between the metallized films.

[0010]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a schematic view showing a winding device for an element body of a metallized film capacitor, and the winding device realizes a film capacitor manufacturing method.

In the figure, metallized films 1 and 2 are formed by vapor-depositing metal A on a film F and integrating them.
The metallized films 1 and 2 are provided with a certain margin. Such metallized films 1 and 2 are stacked and wound to form a wound capacitor.

The winding device is constructed as follows.
That is, the heater rollers 3 and 4 are arranged at a predetermined distance from each other on the circumference of the core portion 5, and the rollers 3 and 4 are pressed toward the center of the core portion 5. is there. The heater rollers 3 and 4 are heated by a device such as a laser that can maintain temperature accuracy.

The film capacitor is manufactured by the above apparatus as follows. First, the metallized film 1 is passed through between the roller 3 and the core portion 5, and the metallized film 2 is passed through between the roller 4 and the core portion 5 and wound on the core portion 5. At this time, the roller 3 pressurizes the metallized film 1 with a predetermined pressure and heats the metallized film 1 so that the metallized film 1 is welded and adhered layer by layer to the winding core side. Similarly, the roller 4 pressurizes the metallized film 2 at a predetermined pressure and heats the metallized film 2 so that the metallized film 2 is welded and adhered to the core side layer by layer.

After pressurizing and heating in this way, the wound element body 6 is taken out from the apparatus, and the element body 6 is sprayed with a metal M on both end surfaces Sa and Sb as shown in FIG. 2 (a). Electrodes are formed by welding and lead wires 7 are welded to the electrodes at both ends Sa and Sb as shown in FIG. 2B, and then resin (not shown) is dipped to form a capacitor.

In the above embodiments, the method for manufacturing the winding film capacitor has been described. However, for the laminated film capacitor as well, the metallized films can be welded and adhered to each other by using the same manufacturing method.

The capacitor manufactured by such a manufacturing method has a small air gap, so that the electrical characteristics are improved, and since it is welded, the mechanical strength is also improved.

Next, the characteristics of the capacitor Ca manufactured by the manufacturing method of the present invention will be compared with the characteristics of the conventional capacitor Cb.

FIG. 3 is a characteristic diagram showing comparative data of the rate of change in capacitance after the oil bath test. In addition, FIG.
It is a characteristic view which shows the comparative data of the exterior resin cracking rate after an oil bath test.

This is a characteristic obtained when the capacitors Ca and Cb are left in an atmosphere of, for example, a temperature of 60 ° C. and a relative humidity of 95% for 24 hours and then immersed in an oil bath of 180 ° C. for 2 minutes. Is. FIG. 3 shows a change in electrostatic capacitance by the above-mentioned test, and FIG. 4 shows a state of the exterior resin crack by the above-mentioned test.

As can be seen from FIGS. 3 and 4, the conventional capacitor Cb has a capacitance change rate of about −2 to −4% and a relatively large change in capacitance. The cracking rate has reached 50% and many cracks occur.

On the other hand, in the capacitor Ca manufactured by the method of the present invention, as can be seen from FIG. 3 and FIG. Also, it can be seen that there is no exterior resin cracking rate and no exterior resin cracking occurs.

FIG. 5 is a characteristic diagram showing the corona start voltage (CSV) and the corona extinction voltage (CEV) when an AC voltage is applied.

As can be seen from FIG. 5, the conventional capacitor Cb has a CSV of only about 250 volts and a CEV of about 180 volts.

On the other hand, the capacitor Ca formed by the manufacturing method of the present invention has a CSV of about 350 V and a CEV of about 280 V.
It can be seen that the CEV is higher than the conventional product. Furthermore, the capacitor Ca manufactured by the method of the present invention
No vibration noise was generated by applying an AC voltage.

As described above, according to the manufacturing method of the present invention, a capacitor Ca having excellent change in capacitance, electrical characteristics such as CSV and CEV, or mechanical characteristics such as cracking of exterior resin and generation of vibration noise can be obtained. Obtainable.

[0026]

As described above, according to the present invention, the metallized film is pressed and heated layer by layer when the capacitor element body is wound or laminated, so that the air gap is eliminated, and the electrical characteristics and mechanical properties are improved. There is an effect that a film capacitor having excellent dynamic characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an outline of an apparatus that realizes a manufacturing method of the present invention.

FIG. 2 is a diagram for explaining a process of forming a capacitor in the present invention.

FIG. 3 is a characteristic diagram showing comparative data of capacitance change rate after an oil bath test.

FIG. 4 is a characteristic diagram showing comparative data of exterior resin cracking ratio after an oil bath test.

FIG. 5 is a characteristic diagram showing a corona start voltage and a corona extinction voltage when an AC voltage is applied to a capacitor.

FIG. 6 is a diagram for explaining element winding of a conventional wound capacitor.

FIG. 7 is a diagram for explaining a conventional method for manufacturing a multilayer capacitor.

[Explanation of symbols]

 1 Metallized Film 2 Metallized Film 3 Heater Roller 4 Heater Roller 5 Core Part

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[Procedure amendment]

[Submission date] May 14, 1991

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

Claim: What is claimed is: 1. A method for manufacturing a capacitor by winding or laminating a metallized film, wherein the metallized film is heated layer by layer during the step of winding or laminating the metallized film. A method of manufacturing a film capacitor, which comprises forming the capacitor through a step of applying pressure.